Ca2+ sensing receptor activation by CaCl2 increases [Ca2+]i resulting in enhanced spatial interactions with calbindin-D28k protein

  • Authors:
    • Jai Parkash
    • Muhammad A. Chaudhry
    • William B. Rhoten
  • View Affiliations

  • Published online on: January 1, 2004     https://doi.org/10.3892/ijmm.13.1.3
  • Pages: 3-11
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Abstract

The extracellular calcium ion concentration, [Ca2+]o, sensing receptor CaR is a G-protein coupled membrane receptor and it is involved in regulating cell proliferation, differentiation, secretion, and apoptosis. Calbindin-D28k is a high affinity calcium-binding protein that plays important roles in modulating the intracellular calcium ion concentration, [Ca2+]i, and thus influences signal transduction. The role of CaR in sensing and responding to [Ca2+]o and spatial interactions of CaR with calbindin-D28k in a distal tubule-like renal cell line are described. Fura-2 loaded Madin Darby bovine kidney (MDBK) cells were exposed to increasing concentrations of CaCl2 and the [Ca2+]i was determined by ratio fluorescence microscopy. The step-wise addition of CaCl2 caused continual increase in [Ca2+]i. The thapsigargin induced increase in [Ca2+]i observed in basal medium was eliminated by pretreatment of MDBK cells with 10 mM CaCl2 thereby suggesting the involvement of endoplasmic reticulum Ca2+ stores in increasing the [Ca2+]i. CaR was localized in the plasma membrane by using confocal microscopy. The confocal microscopy data also showed CaR and calbindin-D28k were co-localized when cells were exposed to 40 mM CaCl2. We postulate that sensing and responses to increasing [Ca2+]o that occur through CaR, increase the [Ca2+]i causing the translocation of Ca2+-bound calbindin-D28k towards CaR.

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January 2004
Volume 13 Issue 1

Print ISSN: 1107-3756
Online ISSN:1791-244X

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Spandidos Publications style
Parkash J, Chaudhry MA and Rhoten WB: Ca2+ sensing receptor activation by CaCl2 increases [Ca2+]i resulting in enhanced spatial interactions with calbindin-D28k protein. Int J Mol Med 13: 3-11, 2004
APA
Parkash, J., Chaudhry, M.A., & Rhoten, W.B. (2004). Ca2+ sensing receptor activation by CaCl2 increases [Ca2+]i resulting in enhanced spatial interactions with calbindin-D28k protein. International Journal of Molecular Medicine, 13, 3-11. https://doi.org/10.3892/ijmm.13.1.3
MLA
Parkash, J., Chaudhry, M. A., Rhoten, W. B."Ca2+ sensing receptor activation by CaCl2 increases [Ca2+]i resulting in enhanced spatial interactions with calbindin-D28k protein". International Journal of Molecular Medicine 13.1 (2004): 3-11.
Chicago
Parkash, J., Chaudhry, M. A., Rhoten, W. B."Ca2+ sensing receptor activation by CaCl2 increases [Ca2+]i resulting in enhanced spatial interactions with calbindin-D28k protein". International Journal of Molecular Medicine 13, no. 1 (2004): 3-11. https://doi.org/10.3892/ijmm.13.1.3